AQA Biology 4.3.1.2
Viral diseases
Three viruses, three ways of spreading. Read the clues, name the virus, and see what controls it.
Combined Science · Higher tier
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One of the most catching.
Measles is one of the most catching diseases there is. In a room with one infected person, most people who aren’t protected will catch it.
If you had to guess, does measles spread like a cold, through the air, or like a cut, through blood?
Measles · HIV · tobacco mosaic virus
Which virus is it?
Viruses live and reproduce inside cells, often destroying the host cell. Each clue below belongs to one of three viral diseases. Pick the disease; the table fills in as you go.
Clue 1 of 8
A fever and a red skin rash
Which disease?
HIV
From HIV to AIDS.
HIV is spread by sexual contact or by exchange of body fluids such as blood, for example when drug users share needles. Step through what happens without treatment.
HIV first causes a flu-like illness.
Tobacco mosaic virus
A virus in plants.
Tobacco mosaic virus (TMV) is a widespread plant pathogen affecting many species, including tomatoes. It spreads by contact: from plant to plant, and on hands and tools. Compare the leaves.
A healthy leaf is evenly green, so all of it can photosynthesise.
Why antibiotics don’t work on viruses: in Antibiotics and painkillers.
Think again · HIV and AIDS
“HIV and AIDS are the same thing.”
Your call
ChooseWhat is the difference between HIV and AIDS?
Sort
Helps, or won’t?
Place each measure.
Tap a card, then tap the box it belongs in. Tap a placed card to take it back.
Command words in this lesson
- Describe
- The symptoms, how it spreads, and how it is controlled.
- Explain
- Why a symptom affects the organism, link by link.
- Compare
- Two diseases, point by point.
Key fact
Measles spreads by droplets; HIV by sexual contact and body fluids; TMV by contact between plants. Antibiotics don’t kill viruses.
Key note · AQA 4.3.1.2
Viral diseases
- Viruses live and reproduce inside cells, often destroying the host cell.
- Measles: fever and a red skin rash; spread by droplets; can be fatal, so most young children are vaccinated.
- HIV: a flu-like illness first; unless controlled by antiretroviral drugs, it attacks immune cells; late stage is AIDS. Spread by sexual contact or body fluids such as blood.
- TMV: a mosaic pattern of discolouration on leaves; less photosynthesis, so less growth.
Photograph this card. Tomorrow, cover it and say each line first.
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Not sure how HIV becomes AIDS?
Drawings are schematic.